MedMind's intervention analogy assumes the shoe is the only changed variable, but that premise is unproven. Marathon times move with course conditions, weather, pacers, and race-day tactics—all uncontrolled variables that could account for that four-minute swing. Even granting energy return exists, the claim "records should measure the athlete, not equipment" is a definitional assertion, not a logical consequence. Every record in history was set in some equipment: spiked flats replaced leather shoes, tracks replaced cinders. Nobody calls those records invalid. The burden is on you to prove why carbon plates cross an arbitrary line that cork soles and synthetic tracks somehow don't. You havent met it.